Fuel pump for engines



July 4, J, F, MALE 2,513,883

FUEL 'PUMP FOR \ENGINES Filed Jan. 15, 1947 Erg-' 372 24 lNvsN-row BjYJohmIMale.

Has ATTORNEY.

Patented July 4, 1950 OFFICE FUEL PUMP FOR ENGINES John F. Male, Easton, Pa., assigner to Ingersoll- Band Company. New York, N. Y., a corporation of New Jersey Application January'ls, 1947, serial No. 122,167

s claims. 1

This invention relates to pumps, and more particularly to a fuel injection pump for internal combustion engines of the Diesel type.

One object of the invention is to prevent the occurrence of high explosion pressures in the engine.

Another object is to enable an engine to operate efficiently on inexpensive fuel oils.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure '1 is a sectional elevation of a fuel pump embodying the invention and showing the pump plunger at the 'end of its suction stroke,

Figure 2 is a view similar to Figure 1 showing the pump plunger in position to move through the effective portion of its pumping stroke,

Figure 3 is a view similar to Figure 1 showing a modified form of the invention,

Figure 4 is a transverse view taken through Figure 3 on the line 4-4, and

Figure 5 is a view similar to Figure 3 showing still another modified form of the invention.

Referring more particularly to the drawings, designates, in general, a fuel pump embodying the invention and 2| a portion of an engine frame supporting the pump and a cam shaft 22 whereby the pump is actuated. y l

The fuel pump comprises acasing 23 having bore 24 to receive a cylinder 25 the interior of which constitutes a pumping chamber 26. The cylinder has an external shoulder 21 that seats against a shoulder 29 in the casing 23 and-is held thereagalnst by a bushing 29 seating against the upper end of the cylinder 25 and by a head 30 threaded into the end of thel casing 23 and acting against the bushing 29. A portion of the bushing 29 extends into the head 30, and the opposed surfaces of the bushing and the head are bevelled to form seating surfaces for suitable packing material 3|.

The interior of the bushing 29 serves as a discharge port 32 for the pumping chamber 26 and also as a guide for the fluted stem 34 of a check valve 35 which seats against the upper end of the bushing to prevent the return flow of fuel into the pumping chamber. The valve 35 is held thus by a spring 36 acting against the end wall of a bore 31 in the head 30 opening into a delivery pipe 39 connected to the injection nozzle 49 of an engine cylinder 4|, only a fragmentary portion of which is shown.

2 which is actuated by a cam 43 on the cam shaft 22 and a push rod 44 that abuts a cup-shaped member 45 slidableA in the lower portion of the casing 23 and bearing with its end wall against the push rod 44. On the lower end of the. plunger lis a shoulder 45 that supports a seat 41 for a spring 49 arranged within the cup shaped member 45 and the lower portion of the bore 24 to actuated the plunger 42 on its suction stroke. A ring 49 seating against a shoulder 50 in the bore 24 vserves as a seat for the upper end of the spring 49.

The fuel pumped by the plunger i2 is introduced into the pumping chamber through an in-l let port 5| located in such wise that it will be uncovered by the plunger 42 near theend of its4 suction stroke and will thus also be again covered at the beginning of the pumping stroke of the plunger. In the bore 24 and in communication with the inlet port 5| is an annular groove 52 that serves as a supply chamber into which fuel is constantly delivered by a supply conduit 53.

The plunger 42 is of the well known type which, in addition to its function of injecting fuel oil into the engine cylinder 4|, serves to by-pass fuel from the pumping chamber to the inlet port 5| fort controlling the termination of injection. The plunger is accordingly provided with an external slot 54 that leads from the upper end of the plunger downwardly to an annular groove 55 the upper edge 56 of which is of helical shape in order that the ending of the fuel injection into The pumping chamber 23 contains a plunger 42 55 the cylinder 4| may be varied in accordance with power requirements, depending upon the angular relationship of the plunger with the cylinder 25.

The means serving to thus rotate the plunger may also be of a well known type and is shown as comprising a sleeve 51 that is rotatable on the lower portion of the cylinder 25 and having a gear 58 that meshes with a rack 59 slidable in a guideway extending transversely of the casing 23. lThe sleeve 51 extends below the lowermost end of the cylinder 25 and has slots 5| to receive lugs 62 on the plunger 42 for slidably interlocking the plunger with the sleeve.

Means are provided to cause the delivery of the leading portion of the fuel charge to the cylinder 4| at a reduced rate and of a quantity which will ignite without objectionable detonation and will serve as a pilot flame for igniting the particles of the succeeding main body of fuel issuing from the spray nozzle 40. To this end the cylinder 25 is provided with a metering pas- Pump,

ananas guppen; int the supply side of the as for example into the inlet port and its opposite end or port Il is so located and of such extent that communication will exist between it and the annular groove 55 during a" small range of the pumping stroke immediately following the covering of the inlet port 5| by the plunger, as shown in Figure 3 of the drawings.

This period of communication between l, the groove l5 and the passage 83, and the flow area oi' the latter may, oi' course, varywith the ignition qualities of the fuel but will be such as to effect the delivery to the cylinder Il oi' the minimum amount of fuel at the slower rate necessary for flame propagation prior to the entrance of the mainspray of fuel into the engine cylinder.

In operation, as the plunger moves on its in" l jection stroke, from the position in Figure 1, it

f first covers the inlet port 5 I, in the manner shown in Figure 2. The annular groo've 55 is then in communication with the port 84 and some of the fuel will escape from the pumping chamber 25 through the slot 54, the groove 55 and the passage 53 to the inlet port 5|. In this way, the

pressure within the pumping chamber 26 will be will be ignited by theheat of compression to actl` as a pilot name.

The injection of fuel at the reduced rate will terminate when the annular groove 55 moves out of communication with the port 64 and during the remainder ofthe pumping stroke the fuel will be l delivered to the engine cylinder at increased speed and pressure and will .be ignited by the pilot llame at the instant of emergence from the spray nozzle 41|. These stages of injection follow each other successively so that each injection and 4, the pump is provided with an orifice that leads from the annular groove 52 to the pumping chamber,` preferably in the plane of the uppermost edge of the port 5|. 1 communication of the oriflce'65 with the pumping chamber is a slot 66 the uppermost edge 61 of At the point 0f g which lies above the port 5| so that the pumping A chamber will be in communication with the orifice y 55 when the plunger I2 reaches a position to cutorince 50 is shown as ing plane of the plunger 42, and fuel is conveyed thereto by apassage 15 leading from the upper end of the plunger to the orifice which communicates with an annular groove 1| the periphery of the plunger through a radi passage 12.

The groove 1| is located below the groove 5l, and the lowermost end or port 13 of the passage 89 is so positioned thatwhen the plunger covers the inlet port 5| on the pumping stroke a degree of communication will exist between the annular groove 1| and the port 13. During the following initial portion of the effective pumping stroke of the plunger some of the fuel will iiow from the pumping chamber through the channels in the plunger and the passage 69 to the inlet port 5|, and fuel will be delivered to the cylinder 4| at the reduced pressure for propagation of the pilot flame until the annular groove moves out of communication with the port 13. The remainder of the fuel in the pumping chamber 28 will then be delivered to the engine cylinder 4| at the higher pressure and rate of ilow.

I claim:

1. In a fuel pump for engines, a cylinder having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a, reciprocatory piston in the pumping chamber to control the inlet channel and acting to eject fuel from the pumping chamber into the l .discharge channel, and pressure relief means for the pumping chamber controlled by the piston for minimizing the rate of fuel injection from the pumping chamber into the discharge channel at the beginning of the effective portion of each electing stroke of the piston.

2. In a fuel pump for engines, a cylinder having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston in the pumping chamber to control the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, and pressure relief means for the pumping chamber controlled by the piston for minimizing the pressure of the leading end-of a'fuel 'charge entering the dis charge channel.

3. In a fuel pump for engines, a cylinder member having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston member in the pumping chamber controlling the inlet channel and acting to eject fuel from the 'pumping chamber into the discharge channel, and a passage in one member for conveying fuel from the pumping chamber to the supply side of the pumping chamber at the beginning of the effective portion of each ejecting stroke of the piston member.

4. In a fuel pump for engines, a cylinder member having a pumping chamber, supply and discharge channels for conveying fuel to and into the engine cylinder 4|- for the formation of the pilot flame serving to ignite the fuel of increased pressure which follows the closing of the slot 55.

In the form of the invention shown in Figure y 5, fuel is by-passed from the pumping chamber to the supply side of the pump through an oriilce from the pumping chamber, a reciprocatory piston member in the pumping chamber controlling the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, and a passage in one of the members controlled by the piston member for conveying fuel from the pumping chamber to the supply side of the pumping chamber at the beginning of the effective portion of each ejecting stroke of the piston member.

5. In a fuel pump for engines, a cylinder having a pumpingchamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston in the pumping chamber controlling the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, and a passage in the cylinder to convey fuel from the pumping chamber to the supply channel at the beginning of the effective portion of each ejecting stroke of the piston and being controlled by the said piston.

6. In a fuel pump for engines, a cylinder having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston in the pumping chamber controlling the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, and passages in the cylinder and the piston to communicate with each other at the beginning of the ejecting stroke of the piston for conveying fuel from the pumping cnamber to the inlet channel during the initial effective portion of the ejecting stroke of the piston.

7. In a fuel pump for engines, a cylinder having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston in the pumping chamber to control the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, ports and passages in the cylinder and the piston cooperating Y with each other to vary the ending of fuel injection into the discharge channel during the pumping stroke of the piston in accordance with variations in the angular positions of the piston in the cylinder, means for varying the angular positions of the piston in the cylinder, and a passage in the cylinder to communicate with the passage in the piston for conveying fuel from the pumping chamber to the inlet channel at the beginning of the effective portion of the ej ecting stroke of the piston.

8. In a fuel pump for engines, a cylinder having a pumping chamber, supply and discharge channels for conveying fuel to and from the pumping chamber, a reciprocatory piston in the pumping chamber to control the inlet channel and acting to eject fuel from the pumping chamber into the discharge channel, and a passage in the cylinder leading from the supply channel to a point in the piston chamber between the supply channel and the discharge channel for the escape of fuel from the pumping chamber to minimize the pressure of the fuel injected into the discharge channel during a portion of the ejecting stroke of the piston and being controlled by the piston.

JOHN F. MALE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,993,759 Stockmeyer Mar. 12, 1935 2,430,801 Bremser Nov. 11, 1947 FOREIGN PATENTS Number Country Date 577,288 Germany 1933 

